Assuming you don't rack your nuts on the top tube make sure the tires are pumped to the correct PSI (probably 110 for a road bike, should be on the tire what the PSI is). If your feet can't reach the ground when you straddle the top tube the bike is just too big. If it's not too big break out the WD-40 (bring some with you) and de-rusty the chain (you'll want a new chain if you decide to take this bike) and make sure all of the derailers shift and that the brakes work.
Once you're confident the bike is road test ready figure out your seat height (pretty straightforward) and then take it for a spin. Depending on how long it's sat in storage it might need all of the cables replaced and a total cleaning (~$100) but ride it first and see if it's smooth and fun or if it doesn't feel like a good fit. It being a 61cm bike it's probably going to feel like you're stretched out like Mr. Fantastic but on the off-chance it doesn't, see how it handles when you take hills and hit the flats wide open.
